The Why: Why is the Metro so deep?

The nice thing about the subway in New York is that it is sub-surface, made from cut-and-cover method a hundred years ago. That system, despite the inconvenience of “being messy” on the street during construction (same as San Francisco, et al), means that riders today can “drop down (or up,in the case of elevated)” one flight of stairs directly to the trains. New York’s old clunky system with it’s express tracks really works great for a lunch-hour pop “from Wall Street to Bloomie’s in 7 minutes”, as the advert used to say. In D.C, you have spent those 7 minutes just getting to the platform.

Seems like they can also be used as bomb shelters

If Woodly Park is deeper than Wheaton, why does Wheaton have the longest escalator?

That what she said